The present invention relates to a container having a cap.
Conventionally, a container having a cap, which includes a container body and a cap, has been provided (refer to Japanese Patent Application Laid-Open (kokai) No. 7-277324).
FIG. 1 is a sectional view of a main portion of the conventional container having a cap.
As shown in FIG. 1, a cap composed of a cover-receiving flange portion 5 and a cover plate 3 is attached to a top panel of a container body 1. The cover plate 3 is supported pivotally with respect to the cover-receiving flange portion 5 while a hinge portion 2 serves as a fulcrum, so that the cover plate 3 can be opened and closed in the direction indicated by the arrow of FIG. 1. When the cover plate 3 is first opened, a user holds an end portion of a seal 4 and pulls it off. The container is thus unsealed while the cover plate 3 is opened. Thus, the user can pour out the contents; i.e., liquid food, from a discharge opening 1A.
The cover-receiving flange portion 5 is disposed on the top panel of the container body 1 along the upper circumferential edge of the discharge opening 1A. The cover-receiving flange portion 5 engages with a hook portion 3A formed along the circumferential edge of the cover plate 3 against their mutual repellent force, thereby establishing a state in which the cover plate 3 is reclosed.
Next, another conventional container having a cap will be described (refer to Japanese Kohyo (PCT) Patent Publication No. 9-501890).
FIG. 2 is a sectional view of a main portion of the other conventional container having a cap.
As shown in FIG. 2, a cap composed of a base flange 15, a movable cylinder 16, and a screw cap 17 is attached to the top panel of a container body 11. Before the container is unsealed, a discharge opening 11A formed in the top panel of the container body 11 is sealed by means of a seal 12. The base flange 15 whose lower portion is formed into a flange portion 13 and whose upper portion is formed into a cylindrical portion 14 integrated with the flange portion 13 is fixedly attached to an upper circumferential edge of the discharge opening 11A.
A female screw 14A is formed on the inner surface of the cylindrical portion 14, and a male screw 14B is formed on the outer surface of the cylindrical portion 14. The movable cylinder 16 is fitted into the cylindrical portion 14 while being screw-engaged with the female screw 14A. A pointed tip portion 16A for rupturing the seal 12 is formed at the lower end of the movable cylinder 16. A plurality of ribs 16B extend vertically on the inner surface of the movable cylinder 16.
The male screw 14B is engaged with a female screw 17B formed on the inner surface of the screw cap 17. A plurality of arms 17A are projected within the screw cap 17, extending downward from the top panel of the screw cap 17. When the screw cap 17 is rotated in a tightening direction, the arms 17A engage with the ribs 16B. Thus, as the screw cap 17 is rotated, the movable cylinder 16 is rotated to be moved downward along the cylindrical portion 14 to a predetermined position.
Before the container is unsealed, the pointed tip portion 16A is located above the seal 12. When the screw cap 17 is rotated in the tightening direction in order to unseal the container, the pointed tip portion 16A ruptures the seal 12. Subsequently, the screw cap 17 is rotated in an opening direction to thereby be removed from the cylindrical portion 14.
When the screw cap 17 is rotated in the opening direction, the arms 17A do not engage with the ribs 16B, but slide on the ribs 16B. For that purpose, a slope portion is formed on at least one of the end faces of the ribs 16B and arms 17A.
The above-described containers having a cap involve the following problems. In the case of the container shown in FIG. 1, after the cover plate 3 is opened, the seal 4 must be pulled off in order to unseal the container; i.e., troublesome work is involved. Also, when the cover plate 3 is closed in such a manner that engagement between the cover-receiving flange portion 5 and the hook portion 3A is incomplete, resealability is impaired, causing leakage of liquid food from inside the container.
In the case of the container having a cap shown in FIG. 2, the seal 12 can be ruptured by rotating the screw cap 17 in the tightening direction, and the screw cap 17 can be removed from the cylindrical portion 14 through rotation in the opening direction. That is, the screw cap 17 can be opened or closed by means of a simple operation. However, a plurality of ribs 16B must be formed on the inner surface of the movable cylinder 16, and a plurality of arms 17A must be projected within the screw cap 17 in such a manner as to extend downward from the top panel of the screw cap 17. Not only does the structure of the movable cylinder 16 and the screw cap 17 become complicated, but also the cost of the container increases.
Particularly, in order to prevent the arms 17A from sliding idly on the ribs 16B when the screw cap 17 is tightened, the arms 17A must be rendered rigid, thereby requiring the designer to consider, for example, the material, structure, and strength of the arms 17A. Thus, the cost of the container is further increased.
An object of the present invention is to solve the above-mentioned problems involved in the conventional containers having a cap, and to provide a container having a cap capable of simplifying an unsealing operation, improving resealability against leakage of the contents thereof, and reducing cost.
To achieve the above object, the present invention provides a container having a cap comprising a container body having a rupture portion for forming a discharge opening, and a cap attached to the container body in correspondence to the rupture portion.
The cap comprises an annular base member fixedly attached to the container body; a screw cap; and a retainer comprising an unsealing member formed at a tip for rupturing the rupture portion, a first screw-engagement portion defined in cooperation with the base member, and a second screw-engagement portion defined in cooperation with the screw cap.
The first and second screw-engagement portions have screw-engagement directions opposite to each other.
The screw cap and the retainer include a rotation control portion, which inhibits relative rotation therebetween when a force not greater than an allowable value is applied thereto and which permits relative rotation therebetween when a force greater than the allowable value is applied thereto.
After the rupture portion is ruptured, the retainer is moved axially by a predetermined amount and is then stopped by stop means.
When the screw cap is rotated for removal, the retainer is advanced, since relative rotation between the screw cap and the retainer is inhibited. As a result, the unsealing member ruptures the rupture portion, thereby forming a discharge opening.
Upon axial advancement of a predetermined amount, the retainer is stopped by the stop means. Subsequently, when the screw cap is rotated further, relative rotation between the screw cap and the retainer is permitted, so that the screw cap can be removed.
As described above, simply by rotating the screw cap counterclockwise, the rupture portion is ruptured to thereby unseal the container, whereby an unsealing operation can be simplified. Also, simply by rotating the screw cap clockwise, the cap can be closed, whereby resealability can be improved to thereby prevent leakage of the contents of the container. Since the structure of the retainer and screw cap can be simplified, the cost of the container can be reduced.
Once the container is unsealed while the screw cap is removed therefrom, screw engagement at the first screw-engagement portion becomes deep. Therefore, even when the screw cap is tightened, the container cannot be restored to the initial state thereof. Accordingly, a user can easily recognize that the container has already been unsealed.
The present invention provides another container having a cap, wherein the first screw-engagement portion comprises a lower retainer male screw formed on the outer surface of a lower portion of the retainer, and a base female screw formed on the inner surface of the base member.
The present invention provides still another container having a cap, wherein the second screw-engagement portion comprises an upper retainer male screw formed on the outer surface of an upper portion of the retainer, and a screw cap female screw formed on the inner surface of the screw cap.
In this case, since the retainer is covered with the screw cap, the second screw-engagement portion can assume a large contact area.
Accordingly, the screw cap can transmit a large torque to the retainer, so that the rotation control portion does not permit easy relative rotation.
The present invention provides a further container having a cap, wherein the second screw-engagement portion comprises a screw cap male screw formed on the outer surface of the screw cap and an upper retainer female screw formed on the inner surface of an upper portion of the retainer.
The present invention provides a still further container having a cap, wherein the screw cap is advanced while being rotated in a removing direction.
The present invention provides a still further container having a cap, wherein, while the rotation control portion inhibits relative rotation, rotation of the screw cap causes rotation and advancement of the retainer, causing the unsealing member to rupture the rupture portion.
The present invention provides a still further container having a cap, wherein the rotation control portion assumes the form of a welded portion formed by welding the screw cap and the retainer.
The present invention provides a still further container having a cap, wherein the stop means comprises a stepped portion formed on the retainer and an upper surface of the base member.
In this case, there is no need for providing a specific stopper for stopping the retainer. Accordingly, not only can the structure of the container be simplified, but also the cost of the container can be reduced.